USArray Data

• USArray Data Overview
• Transportable Array Overview
• Reference Network Overview
• Flexible Array Overview
• Magnetotelluric Overview
• All USArray Stations
• Quality Control
• Data Access
• Data Access Examples
• DMC EarthScope stats

USArray Data Overview

The USArray component of the EarthScope experiment was a continental-scale seismic observatory designed to provide a foundation for integrated studies of continental lithosphere and deep Earth structure over a wide range of scales. USArray will provide new insight and new data to address fundamental questions in earthquake physics, volcanic processes, core-mantle interactions, active deformation and tectonics, continental structure and evolution, geodynamics, and crustal fluids (magmatic, hydrothermal, and meteoric).

Learn more at the USArray website »

The EarthScope DMC is the final archive and distribution point for all raw USArray data from each sub-component: Transportable Array, Reference Network (Backbone/Permanent Array), Flexible Array and Magnetotelluric Array.

The DMC’s Virtual Network concept can be used to select various components of USArray data. The following table illustrates the scope of the USArray virtual networks:

USArray Transportable Array

The Transportable Array is a set of 400 broadband stations that will, over the 10 year course of the project, traverse the conterminous United States. The DMC receives 40 and 1 samples/second seismic data streams from each site in addition to related state-of-health data in real-time. Since mid-2010, atmospheric sensors have been installed at the TA stations. Information about these sensors is available at usarray.org Atmospheric.

Station lists

Station maps

Station reports

USArray Reference Network (including Backbone/Permanent Array)

The Reference Network is composed of permanent stations at a roughly 300 km spacing across the United States and includes the 39 EarthScope-funded Permanent Array stations. The DMC receives 40 and 1 samples/second seismic data streams from most sites.

Station lists

Station maps

USArray Flexible Array

The Flexible Array is a set of broadband and active-source oriented instruments deployed on a temporary basis according to individual proposal (the PASSCAL model). Data rates and availability from Flexible Array deployments depend on the individual proposals.

Station lists:

Station maps

USArray Magnetotelluric

The magnetotelluric (MT) component of USArray consists of 7 permanent MT stations and a mobile array of 20 MT stations that will each be deployed for a period of about one month in regions of identified interest with a spacing of approximately 70 km.

Station lists

Station maps

All USArray Stations

Station lists

Station maps

USArray Quality Control at the DMC

The DMC performs both automated and manual quality control on USArray data. A small team of analysts review raw USArray data regularly in addition to performing higher level quality control measurements. More details are available on the USArray Quality Control Overview page.

To Request USArray Data from the DMC

All USArray data at the DMC is managed within the existing DMC infrastructure along with all the other, non-USArray data at the DMC. This means that USArray data is available via all the DMC’s traditional request mechanisms.

Before requesting data for the first time, we recommend that you learn about requesting and using EarthScope data in general. A good place to start is on the EarthScope DMC Data page.

Real-time data: EarthScope distributes near-real time miniSEED data directly from our real-time collection system (BUD). Click here for details about getting data from our real-time systems. The recommended method for receiving real-time data feeds is with the DMC’s SeedLink service.

Transportable Array and Reference Network: Data from both the Transportable Array and Reference Network are delivered to the DMC in near-real time in SEED format. It is available via all the DMC’s traditional request mechanisms including near-real time. Approximately 7 days after arriving at the DMC the data are copied to the primary archive making them available to all request mechanisms. The data remain in, and are available via, the real-time collection system (BUD) for two months.

Transportable Array SEED data qualities (in order of increasing preference)

Transportable Array data do not contain routine timing or other corrections, the differences in the data qualities is primarily completeness and, in the case of TA Final data sets, richness in terms of included data quality bits in the Mini-SEED headers.

Most DMC request mechanisms will default to returning the highest quality data, or a mix thereof, available for the request. Some request mechanisms also allow selection of specific qualities.

Transportable Array Channel Descriptions

The following is a list of all channels collected for the Transportable Array. Not all of these channels are available in real-time, and not all channels are available for every station.

sps — samples per second

Additional channels for a Strong Motion sensor (Kinemetrics EST Episensor, 2g, 10V/g)

Additional channels for a Vaisala WXT-520 weather station

Flexible Array

Flexible Array experiments are usually conducted like traditional IRIS PASSCAL experiments in that data is retrieved from the field at specific intervals, sent to the PASSCAL Instrument Center and finally shipped to the DMC. These data are available via all “the DMC’s traditional request mechanisms”/ds/nodes/dmc/tools/ shortly after being received at the DMC with the access method dependent on the data type (either the SEED archive or Assembled data sets).
In some cases Flexible Array experiment data are telemetered in near-real time to the DMC in which case the data is managed similarly to Transportable Array, Reference Network or other real-time data feeds.

USArray Data Access Examples

This section is not intended to be an exhaustive tutorial for DMC data access, that function is served by the Tools page. Instead the purpose of these examples are to provide a brief illustration of and kickstart for data access.

Real-time data feeds

The preferred method to get continuous, real-time data feeds from USArray stations is to use the EarthScope DMC’s SeedLink service. Note that most but not all USArray stations are delivered to the DMC in real-time.
SeedLink client software exists for BRTT’s Antelope, Earthworm, SeisComP and a command line client, slarchive, that will write Mini-SEED data directly into the directories and files of your chosing. In the case of Antelope and Earthworm, client programs are included with the recent releases, otherwise source code for client software can be found on the SeedLink service overview page.

BREQ_FAST

breq_fast is an email-based request mechanism. A user sends a formatted request to breq_fast@iris.washington.edu, after which the user is notified by email when the request is ready to download from the DMC. The breqfast format is described here.
As a simple example, requesting a 40-minute window of data from the LHZ channel of every TA network station could be done by sending the following in the body of an email to breq_fast@iris.washington.edu:

.NAME Joe Researcher
.EMAIL joe@university.edu
.MEDIA FTP
.LABEL TA-TongaEvent
.END
* TA 2006 05 03 15 30 00.0 2006 05 03 16 10 00.0 1 LHZ

Note that this request only includes the TA network stations (the stations installed by EarthScope specifically for the Transportable Array). To request data from all Transportable Array stations including the shared and cooperative stations replace the TA network code with the _US-TA virtual network code.

Web Services

EarthScope web services provides direct access to data and metadata archived at the DMC.

Sample queries:

• http://service.iris.edu/fdsnws/station/1/query?net=TA&startafter=2013-01-01&output=text
• http://service.iris.edu/irisws/timeseries/1/query?network=TA&station=Z55A&location=—&channel=BHZ&starttime=2013-03-10T22:30:00&endtime=2013-03-11T02:00:00&bpfilter=0.01-0.1&output=plot